My thoughts are also that since the vaccine group was younger it had implications that the vaccine itself was more likely to hit young and healthy people while

My thoughts are also that since the vaccine group was younger it had implications that the vaccine itself was more likely to hit young and healthy people while covid older and people potentially with cardiovascular issues already existing. It would make it more likely to show in results that post covid people had the worst complications after. Because it was very specifically young men who were hit, it isn't easy to compare to a random post covid cohort. Even after trying to control for everything I don't think it is feasible.